Abstract
Background: The adaptive antiviral immune response requires interaction between CD8+ T cells, dendritic cells, and Th1 cells for controlling SARS-CoV-2 infection, but the data regarding the role of CD8+ T cells in the acute phase of COVID-19 and post-COVID-19 syndrome are still limited.
Methods: . Peripheral blood samples collected from patients with acute COVID-19 ( n = 71), convalescent subjects bearing serum SARS-CoV-2 N-protein-specific IgG antibodies ( n = 51), and healthy volunteers with no detectable antibodies to any SARS-CoV-2 proteins (HC, n = 46) were analyzed using 10-color flow cytometry.
Results: Patients with acute COVID-19 vs. HC and COVID-19 convalescents showed decreased absolute numbers of CD8+ T cells, whereas the frequency of CM and TEMRA CD8+ T cells in acute COVID-19 vs. HC was elevated. COVID-19 convalescents vs. HC had increased naïve and CM cells, whereas TEMRA cells were decreased compared to HC. Cell-surface CD57 was highly expressed by the majority of CD8+ T cells subsets during acute COVID-19, but convalescents had increased CD57 on ‘naïve’, CM, EM4, and pE1 2-3 months post-symptom onset. CXCR5 expression was altered in acute and convalescent COVID-19 subjects, whereas the frequencies of CXCR3+ and CCR4+ cells were decreased in both patient groups vs. HC. COVID-19 convalescents had increased CCR6-expressing CD8+ T cells. Moreover, CXCR3+CCR6- Tc1 cells were decreased in patients with acute COVID-19 and COVID-19 convalescents, whereas Tc2 and Tc17 levels were increased compared to HC. Finally, IL-27 negatively correlated with the CCR6+ cells in acute COVID-19 patients.
Conclusions: We described an abnormal CD8+ T cell profile in COVID-19 convalescents, which resulted in lower frequencies of effector subsets (TEMRA and Tc1), higher senescent state (upregulated CD57 on ‘naïve’ and memory cells), and higher frequencies of CD8+ T cell subsets expressing lung tissue and mucosal tissue homing molecules (Tc2, Tc17, and Tc17.1). Thus, our data indicate that COVID-19 can impact the long-term CD8+ T cell immune response.
Keywords: CD3+CD8+; COVID-19; COVID-19 convalescent; IL-27; SARS-CoV-2; Tc1; Tc17; Tc2; chemokine receptors; memory CD8+ T cells; post-COVID-19 syndrome.
【저자키워드】 COVID-19, SARS-CoV-2, COVID-19 convalescent, post-COVID-19 syndrome., chemokine receptors, IL-27, CD3+CD8+, memory CD8+ T cells, Tc2, Tc17, Tc1, 【초록키워드】 immune response, adaptive, antibody, SARS-COV-2 infection, CD8+ T cells, dendritic cells, flow cytometry, chemokine, memory, serum, IgG antibody, cells, Patient, convalescent, expression, patients, CD8+ T cell, mucosal, Interaction, Frequency, Memory cells, antiviral immune response, tissue, subject, acute phase, post-symptom onset, syndrome, naïve, lung tissue, CXCR5, CD57, acute COVID-19, SARS-CoV-2 protein, CD8+, TEMRA, Cell, homing, described, analyzed, collected, detectable, elevated, patient group, majority, subjects, expressed, correlated, upregulated, expressing, senescent, subset, Th1 cell, healthy volunteer, Peripheral blood sample, TEMRA cell, 【제목키워드】 CD8+, polarization,